Artificial board and method of forming the same



Jan. 23, 1934. c, JLSTRQBEL 1,944,533

ARTIFICIAL BOARD AND METHOD OF FORMING THE SAME Filed Sept. 12, 1932 )VWMM/M Patented Jan. 23,

UNITED STATES PATENT OFFICE ARTIFICIAL BOARD AND METHOD OF FORMING THE SAME Application September 12, 193 Serial No. 632,829

5 Claims.

The invention relates to the manufacture of artificial board more particularly designed for use in the manufacture of tops for automobile bodies, but also suitable for various other uses. It is the primary object of the invention to obtain a product which can be manufactured at very low cost and which nevertheless possesses the desirable characteristics of more expensive products. To this end the invention consists in the construction as hereinafter set forth.

In the drawing:

Figure 1 is a perspective view of a board of my improved construction;

Figure 2 is a longitudinal section illustrating the manner of preparing the facing material;

Figure 3 is a similar view showing the manner of preparing the body material;

Figure 4 is a similar view with the facing material and body material assembled;

Figure 5 is a similar view illustrating a modified method of manufacture.

The body material which I employ in forming my improved board is an integrated fibrous or cellulous material which forms a comparatively rigid structure which is relatively light in weight and which has vibration absorption qualities which particularly adapt it for automobile tops. Such a material is that which is commercially known as Celotex board. However, such a board of itself would be unsuitable for either an automobile top or for any other uses where it is desirable to have a smooth or polished exterior finish of a durable nature. This is for the reason that the fibres or particles of the material are not strongly united to each other and also have voids between the same which form a rough surface.

This defect in the character of the body material might be remedied by providing a facing therefor of other material, but materials that have heretofore been used for such purpose materially increase the cost of manufacture. With the present invention a smooth durable exterior finish is obtained through the use of a facing material which is low in cost and by a simple and inexpensive process of manufacture.

The material which I employ for the finished surface is preferably an absorbent unsized paper sheet or slack sized sheet, such for instance as Kraft, rag or jute paper. One side of this sheet is surfaced with a rubber compound suitable for vulcanizing and which is dispersed in either naptha or water solution. This compound may be applied by spreading it on one side of the sheet by the usual knife method or roller coating, the compound being of such consistency as to penetrate part way through the sheet, preferably one half the thickness thereof. This causes the rubber to surround the fibers for a sufficient distance to greatly increase the strength and tenacity of the sheet, particularly against splitting, and which also has the effect of reducing the stretch of the paper.

Before this facing material can be applied to the body board, the latter must be treated to fill the pores or voids in its surface portion and to also strengthen this portion. The preferable treatment is by applying three coats of a compound rubber solution suitable for vulcanizing, one coat of low viscosity which soaks into the board, a second layer of slightly greater viscosity and a third layer of still greater viscosity. These layers are applied successively, each after the solvent has dried from the previously applied layer. As a result, a smooth surface is obtained, all of the pores in the board on the top side being closed with suflicient impregnation of the fibers to strengthen and waterproof the same.

The treated paper is then applied with its treated surface adjacent to the coated surface of the board, and as these surfaces are still tacky, they will adhere to each other. The further treatment of the board depends upon the specific use to which it is to be put. Where not exposed to the weather, the paper may be painted or otherwise suitably surfaced, and the assembled board subsequently vulcanized. If on the other hand the material is designed for a vehicle body top, where it is exposed to the weather, the finish must be of a weatherproof composition. This preferably consists of a primer especially adapted to take a lacquer finish such for instance as oil base red metal primer, bakelite or various synthetic primers. The paper is sprayed or roll coated with the primer which penetrates between the fibers in the upper half of the sheet, impregnating the same. The board is then heat treated to vulcanize the rubber and this at the same time bakes the primer preparing the top surface for the lacquer, so that it will prevent the penetration of the lacquer into the rubber.

As illustrated in Figures 1 to 4, A is the paper sheet which as shown in Figure 2 is coated on one side with the compound rubber B applied thereto by suitable means such as the roller C. D is the Celotex board which has applied to one surface thereof a plurality of coats of rubber compound solution as indicated at E. The paper facing is then applied to the body board with their coated surfaces in contact as indicated in Figure 4.

Various alternative methods may be used.in preparing my improved product, and in Figure 5 I have illustrated one where the paper facing and the body board are simultaneously treated. Thus as shown, the paper is fed from a roll F under a presser roll G in contact with the upper surface of the Celotex board, both being fed together between the roller G and a lower roller H. The rubber material is fed from a supply tank I into the space between the roller G and board D on the rear side of the roller, and is thus rolled in between the facing paper and the board to impregnate each at the same time.

What I claim as my invention is:

1. An artificial board comprising a body of integrated fibrous material, a facing formed of a relatively thin sheet of paper and a layer of vulcanized rubber compound therebetween penetrating into said body and filling the surface voids thereof and also penetrating part way through the paper sheet.

2. An artificial board comprising a body of integrated fibrous material, a facing formed of a relatively thin sheet of paper, an intermediate layer of vulcanized rubber penetrating into said body and filling the surface voids thereof and also penetrating part way through the paper to surround the fibers, and a finishing coating applied to the outer face of the paper.

3. An artificial board comprising a body of in-- tegrated fibrous material, a facing formed of a relatively thin sheet of paper, a layer of vulcanized rubber compound therebetween penetrating into the body and filling the surface voids thereof and also penetrating part way through the paper sheet to surround the fibers thereof, a primer applied to the outer surface of the paper penetrating part way through the sheet and a lacquer finish applied to the said primer.

4. The method of forming an artificial board which consists in assembling a body formed of integrated fibrous material with a paper facing, impregnating the fibers of both the body and the paper facing with a rubber compound which fills the surface voids in the body and penetrates part way through the paper, and in vulcanizing the rubber.

5. The method of forming an artificial board which consists in assembling a body formed of integrated fibrous material with a paper facing, impregnating the fibers of both the body and the paper facing with a rubber compound which fills the surface voids in the body and penetrates part way through the paper, applying a finish coating to the outer surface of the paper to penetrate part way therethrough, and in heat treating to simultaneously vulcanize the rubber and bake the exterior finish.

CLARENCE J. STROBEL. 

